Cancer is a group of diseases characterized by the uncontrolled growth and spread of abnormal cells. There are many different types of cancer treatment, including traditional therapies (such as surgery, chemotherapy, and radiation therapy), newer forms of treatment (targeted therapy), and complementary and alternative therapies. It is becoming increasingly evident that cancers are dependent on a number of altered molecular pathways and can develop diverse mechanisms of resistance to therapy with single agents. Therefore, combination regimens may provide the best hope for effective therapies with durable effects.